With the possible exception of the Nobel awards, physicists seem to get all the press these days, whether they're doing quantum level work at the LHC, or cosmology via the latest satellite data. Biologists, not so much. It's too bad, because Richard Lenski
is running one of the great evolutionary experiments of our time
, and it's producing interesting results.
Lenski and his team have raised 55,000 generations of E. coli, the equivalent in human terms, of over a million years of evolution. These bacteria normally feed on glucose, a sugar, which is stabilized in solution by sodium citrate, not a chemical that E. coli can typically metabolize. In Lenski's lab, however, one strain has evolved to eat the citrate
, not the glucose. Because Lenski deep-freezes samples every 500 generations. They were able to track the mutations
that led to this change. One of my favorite science journalists, Carl Zimmer
, has been following this work for over a decade with reports like the one above.
Lenski, who was awarded a MacArthur grant in 1996, combines ecology and genetics to create experiments that illustrate the role of population dynamics in evolution, and his research supports the "punctuated equilibrium
" model suggested by Steven J Gould and Niles Eldridge. In addition to lab work showing evolution occurring "in the flesh", Lenski has also published work using computer simulations
that advance understanding of evolutionary mechanisms.